A handheld or desktop type calculator largely consists of a keyboard division including various alphanumerical and function keys and a display division for displaying numerals and signs. The casing structure of such an electronic applicance is ordinarily composed of at least two discrete, viz., originally separate component members which are coupled together. These component members may include two members which are formed separately of each other and which are fastened together by means of, for example, screws with a display unit and a key and switch-pad assembly encased between the two component members. The multi-piece construction of such a prior-art casing structure for a calculator requires a disproportionately large number of members in addition to the structural component members thereof. Various jigs as well as large amounts of time and labor are thus necessitated for the assembly of a calculator using such a casing structure. This inevitably results in low production efficiency and high production cost of electronic appliances such as handheld or desktop calculators.
It is accordingly an important object of the present invention to provide utmost ease of assembly and economy of production for the manufacture of a relatively small sized or portable-type electronic appliance such as, typically, a handheld or desktop calculator.
It is another important object of the present invention to provide a one-piece or totally unitary casing structure of a relatively small sized or portable-type electronic appliance such as a handheld or desktop calculator.
It is still another important object of the present invention to provide an improved casing structure of an electronic appliance, the casing structure being characterized by a totally unitary construction provided by integral panel sections coupled together by hinge connections to permit significant reduction in the number of the component members and elements in assembling the appliance.